1. University of Colorado, Denver, Colorado
2. Department of Medicine, University of California, San Francisco, California
3. Veterans Affairs Medical Center, San Francisco, California
4. Pennington Biomedical Research Center, Baton Rouge, Louisiana
5. Division of Infectious Diseases, Veterans Affairs Medical Center, and Emory University School of Medicine, Decatur, Georgia
6. Department of Medicine, Veterans Affairs Medical Center New York Harbor Healthcare System and New York University School of Medicine, New York, New York
7. Division of Research, Kaiser Permanente, Oakland, California
8. Department of Epidemiology and Biostatistics, University of California, San Francisco, California
9. Department of Biostatistics, University of Washington, Seattle, Washington